Medical devices are often used as diagnostic devices and/or therapeutic devices in diagnosing and/or treating medical conditions of patients. For example, a blood glucose meter is used as a diagnostic device to measure blood glucose levels of patients suffering from diabetes. An insulin infusion pump is used as a therapeutic device to administer insulin to patients suffering from diabetes.
Diabetes mellitus, often referred to as diabetes, is a chronic condition in which a person has elevated glucose levels that result from defects in the body's ability to produce and/or use insulin. There are three main types of diabetes. Type 1 diabetes can be autoimmune, genetic, and/or environmental and usually strikes children and young adults. Type 2 diabetes accounts for 90-95% of diabetes cases and is linked to obesity and physical inactivity. Gestational diabetes is a form of glucose intolerance diagnosed during pregnancy and usually resolves spontaneously after delivery.
In 2009, according to the World Health Organization, at least 220 million people worldwide suffer from diabetes. In 2005, an estimated 1.1 million people died from diabetes. The incidence of diabetes is increasing rapidly, and it is estimated that between 2005 and 2030, the number of deaths from diabetes will double. In the United States, nearly 24 million Americans have diabetes, and an estimated 25% of seniors age 60 and older are affected. The Centers for Disease Control and Prevention forecast that 1 in 3 Americans born after 2000 will develop diabetes during their lifetime. The National Diabetes Information Clearinghouse estimates that diabetes costs $132 billion in the United States alone every year. Without treatment, diabetes can lead to severe complications such as heart disease, stroke, blindness, kidney failure, amputations, and death related to pneumonia and flu.
Diabetes is managed primarily by controlling the level of glucose in the bloodstream. This level is dynamic and complex, and is affected by multiple factors including the amount and type of food consumed, and the amount of insulin (which mediates transport of glucose across cell membranes) in the blood. Glucose levels are also sensitive to exercise, sleep, stress, smoking, travel, illness, menses, and other psychological and lifestyle factors unique to individual patients. The dynamic nature of blood glucose and insulin, and all other factors affecting blood glucose, often require a person with diabetes to forecast blood glucose levels. Therefore, therapy in the form of insulin or oral medications, or both, can be timed to maintain blood glucose levels in an appropriate range.
Management of diabetes is time-consuming for patients because of the need to consistently obtain reliable diagnostic information, follow prescribed therapy, and manage lifestyle on a daily basis. Diagnostic information, such as blood glucose, is typically obtained from a capillary blood sample with a lancing device and is then measured with a handheld blood glucose meter. Interstitial glucose levels may be obtained from a continuous glucose sensor worn on the body. Prescribed therapies may include insulin, oral medications, or both. Insulin can be delivered with a syringe, an ambulatory infusion pump, or a combination of both. With insulin therapy, determining the amount of insulin to be injected can require forecasting meal composition of fat, carbohydrates and proteins along with effects of exercise or other physiologic states. The management of lifestyle factors such as body weight, diet, and exercise can significantly influence the type and effectiveness of a therapy.
Management of diabetes involves large amounts of diagnostic data and prescriptive data acquired in a variety of ways: from medical devices, from personal healthcare devices, from patient-recorded logs, from laboratory tests, and from healthcare professional recommendations. Medical devices include patient-owned bG meters, continuous glucose monitors, ambulatory insulin infusion pumps, diabetes analysis software, and diabetes device configuration software. Each of these systems generates and/or manages large amounts of diagnostic and prescriptive data. Personal healthcare devices include weight scales, blood pressure cuffs, exercise machines, thermometers, and weight management software. Patient recorded logs include information relating to meals, exercise and lifestyle. Lab test results include HbA1C, cholesterol, triglycerides, and glucose tolerance. Healthcare professional recommendations include prescriptions, diets, test plans, and other information relating to the patient's treatment.
There is a need for a handheld device to aggregate, manipulate, manage, present, and communicate diagnostic data and prescriptive data from medical devices, personal healthcare devices, patient recorded information, biomarker information, and recorded information in an efficient manner. The handheld device can improve the care and health of a person with diabetes so that the person with diabetes can lead a full life and reduce the risk of complications from diabetes.
Additionally, to effectively manage the care and health of the patient, there is a need for the handheld device to communicate with and process information received from other medical devices and systems. A handheld device may receive patient information from a number of different sources, such as an insulin pump, a continuous glucose monitor, a computer program, user input, etc. In order to accurately utilize this information, the handheld device may need to calibrate the information received from these sources. For example, a handheld diabetes managing device may receive, from a continuous glucose monitor, raw data that is related to a glucose level of a patient. In order to make use of this raw data, the handheld diabetes managing device may need to be calibrated to correlate the received raw data with a measured blood glucose level of the patient. The accuracy of this calibration can affect the care and treatment of the patient. Accordingly, there is a need for a method of calibrating a handheld diabetes managing device to determine an accurate estimated glucose level of a patient from data received from a continuous glucose monitor.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.